rss twitter

Down the Rabbit Hole
Paul Kiritsis, PsyD Clinical Psychology, DPhil., MA (History)


The Eternal Debate: Are Our Lives Predetermined or Not? (Biology and Neurophysiology)

Paul Kiritsis - Friday, March 25, 2016

The eternal debate between determinism and non-determinism could also be situated and analyzed within a reductionist scientific paradigm, viewing mind as an emergent property of differentiated albeit integrated neural architecture. To understand our privileged position at the uppermost echelon of the evolutionary world tree we must recourse briefly to the gene, the biomolecular mechanism responsible, in part, for resistance to external conditions thermodynamically downhill in nature and for the prominence of upward causation in higher-order organisms. The countercurrent to eternal decomposition offered by genetic control of life is, to all intents and purposes, a bittersweet affair. By coding for specificity of functional organization, in other words blueprints for explicit body plans preserved because they’ve demonstrated prior success in the maintenance of internal order against the disharmonious forces of the external world, genes ensure the continued survival of particular species, including our own. It seems there’s some critical survival value to the possession of genes. However, by fine-tuning species-specific user interfaces replete with perceptual categories, preference sieves, and interaction patterns, and preprogramming the function of committing networks of cells or structures dedicated to the aforementioned prenatally, biological nature has expedited modes of being and perceptual predicates oblivious to the structural, causal complexity of the cosmos and sometimes impervious to social manipulation or control. So much is accounted for and immutably hardwired into the organism before birth that it doesn’t leave much room for creative violation or modulation of the projected life trajectory.

Looking at complex forms of life purely from a neurophysiological level controlled by genes, there is no “freedom” or filter-free window in any objective sense, only neurologically-based world simulators with perceptual interfaces and a priori functioning informed by genetic and molecular programs. The interfaces themselves mediate behavior within environmental niches. We wind up and recompose ourselves, generation after generation, knowing full well that our visual system will only register middle-sized objects within 400-700 nm of the electromagnetic spectrum; that bursting into tears as infants is most likely an implicit sign of hunger; and that purposively avoiding open savannah in central Africa will decrease our likelihood of becoming the next prey item of an apex predator like the lion. Despite inter- and intraspecies variation, perceptual interfaces are ubiquitous and bind life on Planet Earth to informed progression through quantum states, either through the law of attraction or by causal means. Biological nature is set in stone and predetermined.

            Even though historical elucidations of our self-animating nature differ on innumerable points pertaining to the complex evolutionary shift from non-biological material to the replication and expression of genetic information, most scientists have reached a consensus regarding which higher-order qualities separate us from our nearest hominid ancestors, the chimpanzees. These qualities, a propensity for art, science, culture, symbolization, and artificial realities made possible by metaphorical mind-space in conjunction with semantic language, cannot be accounted for by DNA megalomolecules and genetic selection. There is no way a miniscule four percent difference in DNA sequencing between the two genomeshuman and chimpanzeecould ever account for such profound socio-cognitive and cultural advances on our part. The assumed absence of genetic control means we have to credit their collective manifestation to other systems, probably reorganization and self-organization at the behest of gene-environment interactions. Certain emotions and vocalizations like the monolithic phonemes uttered by many primates, for instance, were made possible by morphological structures expressed though genes. Gradually the degradation of functional genes allowed the superintending social environment to transpose utterances into an innovative level of communication marked by semantic language and entwined prosody, a feature unique to humans. The drawn-out phylogenetic process occasioned gross enlargement of our primate brains as well.

            In slowly extricating themselves from a passive, subtractive process of natural selection working through genetic mutations to introduce functions with adaptive value and inhibit or degrade obsolescent ones, the Homo sapiens climbed a level or two above the imposed constraints of biological nature, to realms of social interaction and networking where there is a slight increase in perceived latitudes and the gravitational pull of determinism is weaker. Following a direct comparison between the brains of chimpanzees and humans, one might attribute the neurobiological correlates of this increment in “freedom” to reductions in the percentage of grey matter committed to somatosensory and motor function at birth; to slower maturation of the cerebral cortex; and to cerebral hemispheres with considerably enlarged prefrontal and temporal lobes. What these innovations in cerebral hardwiring did was nothing short of miraculous; they increased mutability within molecular biological syntheses and allowed heterogeneous but connected elements of the external world, everything from learning and subjective mental experience to imagination and thought, to organize and reorganize the functional neural networks of the brain over protracted periods. In doing so psychological capacities hitherto controlled by genes and localized to specific brain regions could now be relinquished to social memory, improvised through mimicry, and henceforth encoded by globally distributed networks. Functional self-organization and neuroplasticity were significant advancements in evolution, allowing the physical maturation of brain structures to be functionally molded by cognitive and emotional traits contained in “higher” social repositories. In many ways the phenomenon speaks to the freeing of life from the shackles of dense matter. Contrary to this more humanistic perspective, life acquires greater tolerance for ambiguity and becomes complacent with the notion that less will be set in stone.        

            In hindsight, life found a way to make social connections count; brains became biological computers and the environment their programmer. No longer confined to strict biological laws, much of life could reap the benefits of social synergy. Our perceived latitudes increased. Even though relegation to electrochemical patterns, themselves partial simulations of objective reality, impede greater comprehension of the universe’s structural and causal intricacy and the extent of our actual confinement, most of the human race seems comfortable utilizing those higher-order traits that make us fundamentally human as a yardstick for freedom. Such traits include intentionality, selective or focal attention, and sequential goal attainment. We’re “free” as long as we can attend to and ignore sensorial and perceptual input entering conscious awareness from internal and external sources, retrieve explicit memories voluntarily, process information semantically, and act after internal deliberation. This is what constitutes freedom for most. It is a delicate commodity, a divine birthright, and a formidable ally all in one. Sometimes taken for granted, sometimes devalued under the auspices of reductive thinking, this freedom is not immune from injury, assault, or degradation. In truth it is highly contingent on normative prenatal and postnatal development and continued functioning of the brain.   

            Knowledge of functional brain areas remained proto-scientific and speculative until the mid-nineteenth century when a railroad construction foreman by the name of Phineas Gage suffered a horrendous cerebral accident. As he tamped dynamite into blasting holes, the dynamite exploded sending the tamping rod under his left cheekbone and out the top of his skull, damaging his frontal lobe. Gage miraculously survived the prefrontal lobotomy but it impelled unbecoming changes to his characterological disposition. The pre-lobotomy Gage was a punctual, courteous, and highly conscientious employee who was a pleasure to be around. In striking contrast the post-lobotomy Gage was a petulant, brazen, and socially disinhibited individual who swiftly acquired a reputation for uttering profanities, avoiding responsibilities, and meandering about without meaning or purpose. Unbeknownst to his employers, family, friends, and physicians at the time, Gage was unlucky enough to suffer assault to the highly differentiated connections of the prefrontal cortex, an associational area responsible for the integration of internal and external data over time, the problem-solving and decision-making processes, and the mediation of prosocial behavior and emotions. We attribute many sociocultural and behavioral variances amid the highest subhuman primates and ourselves to expansion and increased differentiation in these frontal brain areas and damage to them through trauma, stroke, lesions, neurodegenerative conditions, and what not can lead to an immediate cognitive regress, severely hampering our perceived freedom.


            What is more, the kind of manifesting deficit reflects spatial characteristics of the focal abnormality itself. Let’s look at some examples. Bilateral lesions in the medial portions of the frontal gyrus, an area intimately associated with emotions and prosocial behaviors, usually result in atypical displays of ebullient emotion and behaviors void of social decorum.[i] Move the lesion abnormality to anterior parts of the superior, medial, and inferior frontal gyrus and the corresponding subjective experience will encompass impairments in the ability to concentrate, increased distractibility, general apathy, and resistance to showing initiative and taking action. Move it again to the precentral or superior frontal gyrus and the respective individual will suffer motor apraxia, an inability to execute purposive action. The neuroanatomical account we have points fervently towards a deterministic view of life by irradiating mind-matter interdependence. Again, we wish to secure a dignified position in the cosmos but, as always, our perceived sense of freedom is being exposed as nothing more than a subjective phenomenon wrought by complex sociocognitive interactions, stripped and undermined of any empirical validity each time the ancillary physical and biological mechanisms are negatively compromised.

            Naturally one must always retain circumspection when standing on theoretical ground because empirical findings may sway popular opinion toward or away from speculative arguments of absolute determinism at any moment. The secret to unraveling this Gordian knot may depend on scouring the historical annals of experimental psychology, explicitly the ingenious experiments of neuroscientist Benjamin Libet. Renowned for his ground-breaking work on temporal relations between subjective conscious experiences and their neural underpinnings, Libet inadvertently found himself in dialectic opposition to conventional philosophical wisdom vis-à-vis our perceived freedom, our free will, by discovering that the decision to act is unconsciously determined before we become cognizant of the fact.

This counterintuitive and perplexing discovery was made in the following manner: First and foremost, subjects were positioned before a clock with a swiftly rotating spot indicative of time and subsequently commanded to flex their wrists. The subjects were divided into two groups; in one the movement was to be arbitrary and in the other preplanned. To obtain a tangible benchmark for the conscious will to flex, Libet and his crew requested that participants report the position of the spot at the precise time they decided to recourse to action. Irrespective of whether the movement was preplanned or capriciously expressed, standardization of the experimental data showed that the conscious decision preceded the actual motor act, activation of the neuromuscular system, by about 200-150 milliseconds (ms) or a fifth of a second. Intracranial electrophysiology permitting the surveillance of brain waves before, during, and after the mental event showed salient neural activity in the supplementary motor cortex 400-350 ms or approximately a third of a second before the intention to move entered conscious awareness. Strange and perplexing, right? Apparently the observable neurophysiological events we assume to be connected with the voluntary movement itself and later in a causal chain where mental events initiate physical ones, precede conscious intent itself. The movement is initiated by brain processes in unconscious fashion, and awareness of the decision itself is but a passive observer, and a latecomer at that.

Most struggle with the ascription of conscious will to unconscious processes because it flirts openly with a worldview in which intentionality has no empirical validity, a fiction generated and propagated over time to keep the collective self bathed in the best possible light. Why should anyone believe in as disempowering a thing as human protagonists with life courses circumscribed by the imagination of an ineffable author, puppets on strings, when it’s much more satiating and gratifying to think of ourselves as authors of our own meaningful narratives? Who’d want to be like a paramecium reacting reflexively to changes in water temperature?

Libet may or may not have been sensitive to this matter when he construed the correlated mental and neurophysiological phenomena in favor of free will, albeit a delimited one. What he proposed was that the 150 ms or so separating conscious awareness of the will to act and the motor act itself was sufficient time in which the subject could veto the decision and prevent processes of an unconscious origin from reaching fruition. Since there’s no empirical evidence in support of a mandatory role for conscious awareness in the execution of volitional processes or of veto choices being initiated unconsciously,[ii] one could interpret the “conscious veto” as an aspect of a higher-order control function in humans not reducible or describable by “objective” physical events. The “conscious veto” may be a nonphysical regulator of neuronal activity with top-down or causative control of unconscious brain processes. Put differently Libet is proposing there is empirical truth to our perceived freedom, which cannot be couched within a strictly deterministic or reductive account of the cosmos.        



Post has no comments.

Log in to comment on this post

Trackback Link